根据答案写的调用父类。请大神看看哪里错了
<?php
class Car {
public $speed = 0; //汽车的起始速度是0
public function speedUp() {
$this->speed += 10;
return $this->speed;
}
}
//定义继承于Car的Truck类
class Truck extends Car{
public function speedUp(){
$this->speed=parent::spendUp()+50;
}
}
$car = new Truck();
$car->speedUp();
echo $car->speed;我是看着答案一个字一个字打出来的。。。。是这道题有问题么？
